#include <iostream>
#include <vector>
#include <string>

using namespace std;

class Solution {
public:
	vector<vector<int>> generate(int numRows) {
		vector<vector<int>> data;
		if(numRows==0)
			return data;
		if(numRows==1)
		{
			vector<int> firstRow;
			firstRow.push_back(1);
			data.push_back(firstRow);
		}
		else{
			data=generate(numRows-1);
			vector<int> thisRow(numRows);
			thisRow[0]=1;
			thisRow[numRows-1]=1;
			for(int i=1;i<numRows-1;++i)
			{
				thisRow[i]=data[numRows-2][i-1]+data[numRows-2][i];
			}
			data.push_back(thisRow);
		}
		return data;
	}
};

int main(){
	Solution s;
	int n;
	while(true){
		cin>>n;
		vector<vector<int>> data=s.generate(n);
		cout<<data.size()<<endl;
	}
}